77908830865 has 4 divisors (see below), whose sum is σ = 93490597044. Its totient is φ = 62327064688.

The previous prime is 77908830841. The next prime is 77908830893. The reversal of 77908830865 is 56803880977.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56803880977 = 151163 ⋅375779.

It can be written as a sum of positive squares in 2 ways, for example, as 18980297361 + 58928533504 = 137769^2 + 242752^2 .

It is a cyclic number.

It is not a de Polignac number, because 77908830865 - 2⁷ = 77908830737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7790883082 + ... + 7790883091.

It is an arithmetic number, because the mean of its divisors is an integer number (23372649261).

Almost surely, 2^77908830865 is an apocalyptic number.

It is an amenable number.

77908830865 is a deficient number, since it is larger than the sum of its proper divisors (15581766179).

77908830865 is a wasteful number, since it uses less digits than its factorization.

77908830865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15581766178.

The product of its (nonzero) digits is 20321280, while the sum is 61.

The spelling of 77908830865 in words is "seventy-seven billion, nine hundred eight million, eight hundred thirty thousand, eight hundred sixty-five".